Simply Silent DX100 square grille fascia 4\" 100mm extract fan, featuring Ghost Air Movement Technology for quiet running, with humidistat and timer control which boosts when humidity in the room increases while the timer continues to work after the fan is switched off. The timer is adjustable at installation from 30 seconds to 30 minutes. Supplied with wall fitting kit comprising of outer grille, telescopic wall tube, gasket and foam strips. Supplied with 12V transformer.